LACTOBACILLUS ACIDOPHILUS CIP 76.13 AND L. DELBRUECKII SUBSP. BULGARICUS CIP 101027T AS PROMISING MYCOTOXIN DECONTAMINATING AGENTS

Mycotoxins are harmful secondary metabolites produced by fungi which contaminate a wide range of food and feed. Lactic acid bacteria (LAB) show a promising potential to degrade or bind mycotoxins thus reducing their absorption at gastrointestinal level. This study was aimed to investigate the ability of Lactobacillus acidophilus CIP 76.13 and L. delbrueckii subsp. bulgaricus CIP 101027T in removing AFB1, OTA, ZEA and DON in culture media. Mycotoxin removal by viable and heat-inactivated cells was evaluated at pH7, 37°C and 24 h of incubation time, in PBS and MRS containing 1 ?g/mL of each mycotoxin. Residual mycotoxin content in supernatants and cell pellets was determined by UHPLC-FLD/PDA analytical methods. Mycotoxin reduction values differed depending on liquid media. In PBS, viable cells of these strains reduced, on average, ZEA and DON by 57.4 and 30.0%, respectively. AFB1 and OTA reductions in PBS were negligible, being lower than 15%. In MRS, mean values of ZEA and AFB1 reduction were 28.0 and 32.1%, respectively, while OTA and DON were not reduced. Mycotoxin reductions recorded using heat inactivated cells of each strain, tested in PBS or MRS, were significantly lower than those obtained with viable cells. These results suggests that mycotoxin reduction by bacterial strains may occur by a biotransformation process rather than a binding mechanism. In addition, both strains survived at pH 3, 5 and 7 for 24 h in PBS and exhibited lipolytic and proteolytic activities. This study suggests the potential use and broader application of LABs (CIP 76.13 and CIP 101027 T) for mycotoxin reduction in food and feed industry.